1. Field of the Invention
This invention relates to an acetyltransferase activity measuring agent which comprises an arylamine derivative.
2. Description of the Related Art
Tests of renal excretory function by measuring clearance are conventionally known as renal function tests. As one of these tests, creatinine clearance which makes use of creatinine as an endogenous substance is often used clinically to test the physical function in terms of glomerular filtration rate (GFR). In the renal function test by measuring creatinine clearance, however, urine required for the test is preferably collected over 24 hours. The renal function test by creatinine clearance is therefore accompanied by the drawbacks that a substantial time is needed until test results are obtained, the test tends to be affected by the quantity of urine, body movements and the like, and measured values are prone to scattering.
Further, to check the renal plasma flow (RPF), one of parameters of physical function of the kidneys, PAH clearance using p-aminohippuric acid (PAH) is also employed. Although PAH has the merits that it has safety to the human body and can be promptly excreted into urine when administered by intravenous infusion, PAH involves the problems that it is laborious and inflicts pain on subjects because upon conducting a test, continuous intravenous infusion is performed and a catheter is inserted into the bladder to collect urine at predetermined time points.
Incidentally, many of nephritides which cause lowering in renal function are mesangial proliferative, typified by immunoglobulin A (IgA) nephritis. Nephritis having a mesangial proliferative lesion is progressive and has high possibility of resulting in renal insufficiency and the need for dialysis. To determine and diagnose such nephritis, histopathological findings of kidney tissue obtained by biopsy are indispensable. Kidney biopsy and such histopathological findings, however, can be conducted only at a hospital equipped with facilities therefor. To conduct kidney biopsy, a subject has to be hospitalized. Moreover, there is the potential risk that upon biopsy, one or more blood vessels may be damaged or the subject may be affected by an infectious disease.
On the other hand, N-acetylation of an aromatic amine in the human body is a reaction in which acetyltransferase, an enzyme in the body, takes part. It has been reported that acetyltransferase activity is observed on excised organs such as kidneys and livers and also on white blood cells [G. M. Pacifici et al., Xenobiotica 18(7), 849-856 (1988), A. E. Cribb et al., J. Pharmacol. Exp. Ther., 259(3), 1241-1246 (1991)].